package 常用类.day2.复习;

public class Test2 {
    public static void main(String[] args) {
        String s1="abc";
        String s0="abc";
        String s2=new String("abc");
        String s3=new String("abc");
        String s4=s1.substring(0, 3);
        System.out.println(s1==s4);
        System.out.println(s1);
        String s5=s1.concat("");
        System.out.println(s5);
    }
}
